The invention relates to vacuum cleaners and, in particular, to a vacuum motor unit for wet/dry machines.
Vacuum cleaner assemblies capable of picking up liquids such as water present a hazard of electrical shock where such liquids are drawn into contact with electrically conducting parts of the vacuum motor unit. These parts may be electrically energized as the result of an internal short within the motor. Likewise, a hazard may result where an electrically conducting fluid migrates into the motor section of the vacuum unit. In recognition of these or similar dangers to a user, many hand tools and like appliances have in recent years been designed with double insulation so that, as the term implies, two distinct electrically insulating barriers are provided between normally electrified motor elements.
Generally, double insulation techniques have not been applied to vacuum cleaner devices. One double insulated vacuum cleaner motor unit is disclosed in U.S. Pat. No. 3,875,436 to MacFarland. The machine disclosed in this patent, however, is not directly applicable to conventional tank or shop type designs as is the present invention.